Motor and apparatus using the same

ABSTRACT

A motor includes a first vibrator, a plurality of biasing parts that are disposed around the first vibrator and that presses the first vibrator onto a contacting member in contact with the first vibrator, a first pressing member that is biased by the plurality of biasing parts and that includes a pressing part pressing the first vibrator by biasing force of the plurality of biasing parts, and a second pressing member that is biased by the plurality of biasing parts. The first vibrator and the contacting member move relatively by vibrations that occur in the first vibrator. The first and second pressing members integrally moves while the first vibrator moves. The first pressing member and the first vibrator are tiltable around a first direction orthogonal to both of a moving direction of the first vibrator and a biasing direction of the plurality of biasing parts.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a motor and an apparatus using thesame.

Description of the Related Art

A friction drive type ultrasonic motor (vibration-wave motor) using adeformation based on a piezoelectric effect of a piezoelectric elementas a driving source has a generative force larger than that of anelectromagnetic motor and can drive a driven part without providing adeceleration mechanism. Moreover, it drives the driven part usingfriction, thus enabling drive with a large holding force and excellentquietness. Japanese Patent Laid-Open No. 2015-136205 discloses a linearvibration type motor that includes a vibrator having an elastic memberprovided with two pressure contact parts and a piezoelectric element,and a contacted member contacting the pressure contact parts pressed bya pressing spring. Furthermore, Japanese Patent Laid-Open No. 2011-72130discloses a vibration-wave motor mechanism including a configurationdifferent from that of the motor disclosed in Japanese Patent Laid-OpenNo. 2015-136205.

The friction drive type vibration-wave motor can provide a desiredperformance by maintaining the pressing force of a pressure contact partat a predetermined value. Large pressing force increases the generativeforce but suppresses driving vibrations of a vibrating body, thusincreasing consumed power to keep the same speed, wherebyelectromechanical conversion efficiency lowers. Conversely, smallpressing force decreases the generative force. Especially, when twopressure contact parts are provided, balance of the pressing force toboth pressure contact parts are important. Imbalanced pressing force toboth pressure contact parts makes a deformation, which should benormally symmetric with respect to a driving direction, asymmetric,reduces efficiency, and increases differences of various characteristicsaccording to the driving direction.

In Japanese Patent Laid-Open No. 2015-136205, the pressing spring, whichpresses the two pressure contact parts onto the contacted member, isdisposed immediately above the vibrator, and thus stable pressurizationto the two pressure contact parts is realized. However, as the pressingspring is disposed immediately above the vibrator, a thickness of themotor increases.

In Japanese Patent Laid-Open No. 2011-72130, a plurality of tension coilsprings, which are disposed around a laminated piezoelectric element,presses a sliding member and a friction member so as to cause them tocontact each other. However, as the tension coil springs tow the slidingmember and a case member, those displacements are restricted to beingsmall, and it becomes difficult to maintain a stable pressing state ofthe two members to the friction member. Moreover, differences betweencharacteristics of the plurality of tension coil springs are notconsidered.

SUMMARY OF THE INVENTION

In view of the problem, an object of the present invention is to providea motor that is thin and that has stable performance.

A motor according to one aspect of the present invention includes afirst vibrator, a plurality of biasing parts that are disposed aroundthe first vibrator and that are arranged to press the first vibratoronto a contacting member in contact with the first vibrator, a firstpressing member that is biased by the plurality of biasing parts andthat includes a pressing part arranged to press the first vibrator bythe biasing force of the plurality of biasing parts, and a secondpressing member that is biased by the plurality of biasing parts. Thefirst vibrator and the contacting member are arranged to move relativelyby vibrations that occur in the first vibrator. The first and secondpressing members are arranged to move integrally with the first vibratorwhile the first vibrator moves. The first pressing member and the firstvibrator are arranged to be tiltable around a first direction orthogonalto both of a moving direction of the first vibrator and a biasingdirection of the plurality of biasing parts.

An apparatus according to another aspect of the present inventionincludes a motor, and a member that drives by driving force from themotor. The motor includes a first vibrator, a plurality of biasing partsthat are disposed around the first vibrator and that are arranged topress the first vibrator onto a contacting member in contact with thefirst vibrator, a first pressing member that is biased by the pluralityof biasing parts and that includes a pressing part arranged to press thefirst vibrator by the biasing force of the plurality of biasing parts,and a second pressing member that is biased by the plurality of biasingparts. The first vibrator and the contacting member are arranged to moverelatively by vibrations that occur in the first vibrator. The first andsecond pressing members are arranged to move integrally with the firstvibrator while the first vibrator moves. The first pressing member andthe first vibrator are arranged to be tiltable around a first directionorthogonal to both of a moving direction of the first vibrator and abiasing direction of the plurality of biasing parts.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an image pickup apparatus including avibration-wave motor unit according to an embodiment of the presentinvention.

FIGS. 2A and 2B are a plan view and a side view of a vibrator accordingto a first example.

FIGS. 3A and 3B are perspective views of a vibration-wave motor unitaccording to the first example.

FIG. 4 is an exploded perspective view of the vibration-wave motor unitaccording to the first example.

FIG. 5A to 5C are a plan view and sectional views of the vibration-wavemotor unit according to the first example.

FIGS. 6A to 6E are explanatory diagrams of a degree of freedom in motionof the vibrator according to the first example.

FIG. 7 is an explanatory diagram of a relation between a pressing plateand a moving member according to the first example.

FIGS. 8A and 8B are perspective views of a straight guide memberaccording to the first example.

FIGS. 9A to 9D are explanatory diagrams of the straight guide memberaccording to the first example.

FIGS. 10A and 10B are explanatory diagrams of assembly of the straightguide member according to the first example.

FIGS. 11A to 11D are perspective views of a lens driving unit accordingto the first example.

FIGS. 12A and 12B are perspective views of a vibration-wave motor unitaccording to a second example.

FIG. 13 is an exploded perspective view of the vibration-wave motor unitaccording to the second example.

FIG. 14A to 14C are a plan view and sectional views of thevibration-wave motor unit according to the second example.

FIGS. 15A to 15C are explanatory diagrams of a degree of freedom of avibrator according to the second example.

FIG. 16 is an explanatory diagram of a relation between a pressing plateand a moving member according to the second example.

FIG. 17 is a perspective view of a straight guide member according tothe second example.

FIGS. 18A and 18B are explanatory diagrams of a coupling part of thevibration-wave motor unit and a lens unit according to the secondexample.

FIGS. 19A and 19B are perspective views of a vibration-wave motor unitaccording to a third example.

FIG. 20 is an exploded perspective view of the vibration-wave motor unitaccording to the third example.

FIGS. 21A to 21C are a plan view and sectional views of thevibration-wave motor unit according to the third example.

FIGS. 22A to 22C are explanatory diagrams of a degree of freedom of avibrator according to the third example.

FIG. 23 is an explanatory diagram of a relation between a first pressingplate and a second pressing plate according to the third example.

FIGS. 24A and 24B are perspective views of a lens driving unit accordingto the third example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the accompanying drawings, a detailed description willbe given of embodiments of the present invention. Those elements in eachfigure, which are corresponding elements, will be designated by the samereference numerals, and a description thereof will be omitted.

FIG. 1 is a sectional view of an image pickup apparatus (opticalapparatus) including a vibration-wave motor unit (a vibration-wave motoror an ultrasonic motor unit, hereinafter, referred to as “motor unit”)1000 according to an embodiment of the present invention. The imagepickup apparatus according to this embodiment includes an image pickuplens unit 2000 and a camera body 3000. Inside the image pickup lens unit2000, the motor unit 1000 and a focusing lens unit 4000, which isattached to the motor unit 1000, are provided. Inside the camera body3000, an image pickup element 5000 is provided. The motor unit 1000moves the focusing lens 4000 along an optical axis O while capturing animage. An object image is imaged at a position of the image pickupelement 5000, and the image pickup element 5000 generates a focusedimage. In this embodiment, the image pickup apparatus includes the motorunit 1000, but the present invention is not limited to this. Forexample, the motor unit 1000 may be mounted on the other opticalapparatus, such as a lens unit, or may be mounted on an apparatusdifferent from an optical apparatus. Moreover, in this embodiment, theimage pickup lens unit 2000 and the camera body 3000 are integrallyconfigured, but the present invention is not limited to this. The imagepickup lens unit 2000 may be detachably attached to the camera body3000. In other words, an apparatus in the present invention is anapparatus including a vibration-wave motor explained in each example,and a member that drives by driving force from the vibration-wave motor.

FIRST EXAMPLE

Referring to FIGS. 2A and 2B, a description will be given of a vibrator2 included in a motor unit 1000A according to this example. FIGS. 2A and2B are a plan view and a side view of the vibrator 2. FIGS. 2A and 2Bare respectively a plan view and a side view of the vibrator 2. Thevibrator 2 includes driving protrusions 2 a and 2 b, and fixed arm parts2 c and 2 d. To the vibrator 2, a vibrating plate (elastic plate) 3 anda piezoelectric element 4 are fixed with the adhesive. The piezoelectricelement 4 excites ultrasonic vibration by being applied with two-phasehigh frequency voltages, and an elliptical motion on an x-y planeillustrated in FIG. 2B is energized at ends of the driving protrusions 2a and 2 b. In this state, when a friction member comes into frictionalcontact the driving protrusions 2 a and 2 b, the vibrator 2 and thefriction member relatively move. In this example, a rectangular areaA—B, which faces a friction member (contacting member) 7 and includesthe driving protrusions 2 a and 2 b, is a driving force generation area(facing area). Moreover, a plane C, which is orthogonal to therectangular area A×B and the x-axis, and symmetrically divides therectangular area A×B, is a front/rear symmetric plane (first plane), anda plane D, which is orthogonal to the rectangular area A×B and thez-axis, and symmetrically divides the rectangular area A×B, is aleft/right symmetric plane (second plane). The front/rear symmetricplane C includes a direction orthogonal to both of a moving direction ofa moving part and a pressing direction (biasing direction) of pressers(biasing parts), as described below, and the pressing direction of thepressers. Furthermore, the left/right symmetric plane D includes themoving direction of the moving part and the pressing direction of thepressers.

Referring to FIGS. 3A, 3B, 4, and 5A to 5C, a description will be givenof a configuration of the motor unit 1000A. FIGS. 3A and 3B areperspective views of the motor unit 1000A. FIG. 3A is a perspective viewas seen form a top side, and FIG. 3B is a perspective view as seen froma bottom side. FIG. 4 is an exploded perspective view of the motor unit1000A. FIGS. 5A to 5C are a plan view and sectional views of the motorunit 1000A. FIG. 5A is a plan view, and FIGS. 5B and 5C are sectionalviews taken along an x-x line and a z-z line of FIG. 5A, respectively.

A base member 5 is fixed to a fixing member (not illustrated) by thescrews, and fixes a friction member 7 using the screws. The frictionmember 7 comes into frictional contact with the driving protrusions 2 aand 2 b of the vibrator 2 by pressing force (biasing force) of tensioncoil springs 10. A flexible substrate 6 is mechanically and electricallyconnected to the piezoelectric element 4 by the anisotropic conductivepaste, and applies the two-phase high frequency voltages to thepiezoelectric element 4. A vibrator holding frame 8 is integrated withthe vibrator 2 by fixing the fixed arm parts 2 c and 2 d with theadhesive. A pressing intermediary member 9 includes a felt 9 a thatcontacts the vibrator 2, and a high rigid plate 9 b, such as the metal,that receives the pressing force of the tension coil springs 10. Thefelt 9 a transmits the pressing force of the tension coil springs 10 tothe vibrator 2 without preventing the vibrations energized in thevibrator 2.

The four tension coil springs (biasing members) 10 are disposed aroundthe vibrator 2, and generates the pressing force in a negative direction(pressing direction) of the y-axis as pressers in this example. Apressing plate (first pressing member) 11 is biased by the tension coilsprings 10. The pressing plate 11 also includes a spherical protrusion(pressing part) 11 a that abuts against the pressing intermediatelymember 9 on an intersection line of the front/rear symmetric plane C andthe left/right symmetric plane D of the vibrator 2. A coupling sheetmetal 12 is fixed to the vibrator holding frame 8 by the screws. A guidemember 13 is fixed to the base member 5 by the screws through a fixedsheet metal 16 to be parallel to a contact surface of the frictionmember 7 with the driving protrusions 2 a and 2 b. A moving member(second pressing member) 14 is biased by the tension coil springs 10.Rolling balls (rolling members) 19 x, 19 y and 19 z each are sandwichedbetween the guide member 13 and the moving member 14, and receives thepressing force of the tension coil springs 10. An integrated spring 15is a tension coil spring that biases the vibrator holding frame 8 andthe moving member 14 through the coupling sheet metal 12 to beintegrated in the x-axis direction. In this example, a moving part,which includes the vibrator 2, the vibrator holding frame 8, thepressing intermediary member 9, the tension coil springs 10, thepressing plate 11, the coupling sheet metal 12, and the moving member14, relatively moves along the x-axis with respect to the frictionmember 7.

Next, referring to FIGS. 6A to 6E, a description will be given of adegree of freedom in motion of the vibrator 2 according to this example.FIGS. 6A to 6E are explanatory diagrams of the degree of freedom inmotion of the vibrator 2. In FIGS. 6A to 6E, components of the motorunit 1000A unnecessary for the explanation are omitted. FIG. 6Aillustrates the vibrator holding frame 8 and the moving member 14, whichare integrated by biasing force of the integrated spring 15 through thecoupling sheet metal 12. The integrated spring 15 is hooked between ahook part 8 a provided on the vibrator holding frame 8 and a hook part14 b provided on the moving member 14. A reference ball 17 is sandwichedbetween a conical hole part 12 a formed on the coupling sheet metal 12and a conical hole part 14 a formed on the moving member 14. A rollingball 18 is sandwiched between a V-shape groove 8 b formed on thevibrator holding frame 8 and a plane part 14 c formed on the movingmember 14. Sandwiching the rolling ball 18 between the V-shape groove 8b and the plane part 14 c restricts rotation of the vibrator holdingframe 8 and the moving member 14 in the rotational direction (yawdirection) around the y-axis centering the reference ball 17.

FIG. 6B illustrates a sectional view of the motor unit 1000A cut on aplane containing setting centers of the integrated spring 15, thereference ball 17, and the rolling ball 18. Arrows A to C each representforce for acting on the vibrator holding frame 8. The force representedby the arrow A is force for biasing the vibrator holding frame 8 by theintegrated spring 15 to rotate the vibrator holding frame 8 around thereference ball 17. The force represented by the arrow B is force foracting on the V-shape groove 8 b from the plane part 14 c through therolling ball 18. Sandwiching the rolling ball 18 between the V-shapegroove 8 b and the plane part 14 c restricts the rotation of thevibrator holding frame 8 and the moving member 14 around the referenceball 17, that is, the rotation of the vibrator holding frame 8 in theyaw direction is restricted. Then, moments of the forces A and B aroundthe reference ball 17 balances.

The force C is force for acting on the vibrator holding frame 8 throughthe coupling sheet metal 12, balancing with resultant force of theforces A and B as illustrated in FIG. 6C. Thus, the degree of freedom inmotion in the x-axis direction (x-axis translation direction) and thez-axis direction (z-axis translation direction) of the vibrator holdingframe 8 is restricted. Moreover, as the reference ball 17 is sandwichedbetween the conical hole part 12 a and the conical hole part 14 a, thedegree of freedom in motion in the y-axis direction (y-axis translationdirection) of the vibrator holding frame 8 is also restricted.

As described above, in this example, the motion of the vibrator holdingframe 8, which is integrated with the vibrator 2, to the moving member14 has two degrees of freedom in the rotational direction (rolldirection) around the x-axis and the rotational direction (pitchdirection) around the z-axis. In this example, as the vibrator 2 has thetwo degrees of freedom in motion in the roll direction and in the pitchdirection, the driving protrusions 2 a and 2 b of the vibrator 2 canabut against the friction member 7 certainly. Additionally, the forces Ato C, which restrict the degree of freedom in motion of the vibrator 2,balance within one plane, thus not generating unbalance of unnecessaryforce to the driving protrusions 2 a and 2 b.

FIGS. 6D and 6E respectively illustrate states where the vibratorholding frame 8 rotates in the roll direction and in the pitch directionaround the reference ball 17. As illustrated in FIGS. 6D and 6E, therotation in the roll direction moves the driving protrusions 2 a and 2 bup and down along the y-axis direction, and the rotation in the pitchdirection can correspond to differences between positions in the y-axisdirection.

FIG. 7 is an explanatory diagram of a relation between the pressingplate 11 and the moving member 14. The four tension coil springs 10engage each of spring hook parts of the pressing plate 11 and the movingmember 14. As a distance in the y-axis direction between the pressingplate 11 and the moving member 14 is determined by unillustratedcomponents of the motor unit 1000A, the four tension coil springs 10bias the pressing plate 11 and the moving member 14. The four tensioncoil springs 10 are symmetrically disposed at equal intervals from thespherical protrusion 11 a and have the same specification. However,biasing force of each tension coil spring at a predetermined length isnot necessarily the same due to production tolerance, and error in aposition of each of spring hook parts of the pressing plate 11 and themoving member 14 is also caused due to production precision in a singlepart and production error of intervening parts. In this example, thepressing plate 11 is abutted against the pressing intermediary member 9by the spherical protrusion 11 a, and has the degree of freedom inmotion (tilt) in the roll direction and the pitch direction with thespherical protrusion 11 a as a fulcrum.

In other words, the pressing part 11 can tilt around the axis orthogonalto the front/rear symmetric plane C in the left/right symmetric plane Dand around the axis orthogonal to the left/right symmetric plane D inthe front/rear symmetric plane C. The pressing part need not be strictlytiltable around each axis, and is regarded to be tiltable around eachaxis even when shifting by a few mm from each axis. For example,although being different according to performance and a use, shifts maybe about ±0.2 mm. Accordingly, the pressing force of the four tensioncoil springs 10 acting on the driving protrusions 2 a and 2 b from thespherical protrusion 11 a through the pressing intermediary member 9each are adjusted optimally with respect to the production tolerance.

The axis as a center in tilting the pressing plate 11 may be defined asfollows. That is, when a direction orthogonal to a moving direction of afirst vibrator and a pressing direction of a plurality of pressures is afirst direction (z-axis direction), the first pressing member istiltable around the first direction. This definition is common to thefollowing examples.

Moreover, the pressing plate 11 has the degree of freedom in motion inthe roll and pitch directions relative to the vibrator holding frame 8including the pressing intermediary member 9, an attitude of thepressing plate 11 with respect to the moving member 14 is adjusted to bean optimum state regardless of a tilt of the vibrator holding frame 8and a change of the tilt. Thus, the pressing force of each of the fourtension coil springs 10 acting on the driving protrusions 2 a and 2 bfrom the spherical protrusion 11 a through the pressing intermediarymember becomes stable without variations. In addition, although thedistance in the y-axis direction between the pressing plate 11 and themoving member 14 may change, a spring constant of the tension coilsprings 10 can be smaller than that of a plate springs, and this isadvantageous to stabilization of the pressing force.

Besides, as a protrusion 11 b provided on the pressing plate 11 engagesa groove part 8 c as illustrated in FIG. 6B formed on the vibratorholding frame 8, the pressing plate 11 and the moving member 14 areintegrated in the x-axis direction. Accordingly, the pressing force ofthe tension coil springs 10 becomes stable without changing a positionalrelation among the tension coil springs 10, the pressing plate 11, andthe moving member 14 while the moving part moves along the x-axis.

FIGS. 8A and 8B are perspective views of a straight guide memberincluding the guide member 13, the moving member 14, and the rollingballs 19 x, 19 y and 19 z, which are sandwiched between both members.FIGS. 9A to 9D are explanatory diagrams of the straight guide member. Onthe moving member 14, straight guide grooves 14 x, 14 y an 14 z, whichrespectively engage the rolling balls 19 x, 19 y and 19 z, are formed tobe parallel to the x-axis direction (moving direction of the movingpart). The straight guide grooves 14 x and 14 y are tandemly formedalong the x-axis, that is, are separately formed on the same straightline parallel to the x-axis. The straight guide groove 14 z is alsoformed along the x-axis to separate from the straight holding grooves 14x and 14 y in the z-axis direction. When the rolling balls 19 x, 19 yand 19 z rolls, the moving member 14 smoothly moves along the x-axiswith respect to the guide member 13 while receiving the pressing forceof the tension coil springs 10.

FIG. 9A illustrates a state where the guide member 13 and the movingmember 14 abut against the rolling balls 19 x, 19 y and 19 z. FIG. 9Balso illustrates a sectional view of a plane including the rolling balls19 y and 19 z in the state of FIG. 9A. On part of each of the straightguide grooves 14 x, 14 y and 14 z, a surface having an opening angle of60 degrees is formed to be engageable with each rolling ball. On theguide member 13, a guide wall 13 x-y is continuously formed along thex-axis to be opposite to the straight guide grooves 14 x and 14 y and toengage the rolling balls 19 x and 19 y. The guide wall 13 x-y has anopening angle of 120 degrees to be engageable with each rolling ball.Additionally, on the guide member 13, a guide plane part 13 z is formedalong the x-axis in parallel with the x-z plane to be opposite to thestraight guide groove 14 z and to engage the rolling ball 19 z. In thisexample, the surface having the opening angle of 60 degrees is formed onpart of each straight guide groove, but the present invention is notlimited to this. For example, a plane having a predetermined angle withrespect to the x-z plane may be formed along the x-axis on part of eachstraight guide groove, and the whole straight guide groove may be formedas a V-shape groove having a predetermined opening angle. Furthermore,in this example, the guide wall 13 x-y has the opening angle of 120degrees, but the present invention is not limited to this. For example,the guide wall 13 x-y may be formed along the x-axis to have apredetermined angle with respect to the x-z plane as long as beingengageable with each rolling ball.

On the guide member 13, plane parts 13 v and 13 w are formed. The movingmember 14, as described above, includes the four spring hook parts(engaging parts) that each engage the tension coil springs 10. In thestate of FIG. 9A, a restriction part 14 v, which is part of each of twoof the four spring hook parts, is provided to have an interval “a” tothe plane part 13 v in the y-axis direction. On the moving member 14,two stoppers 14 w are also provided to have an interval “a” to the planepart 13 w in the y-axis direction in the state of FIG. 9A.

FIG. 9C illustrates a state where the guide member 13 abuts against themoving member 14 in the y-axis direction, that is, a state where theplane parts 13 v and 13 w respectively engage the two restriction parts14 v and the two stoppers 14 w. FIG. 9D also illustrates a sectionalview of a plane including the rolling ball 19 z in the state of FIG. 9C.In FIG. 9C, the rolling balls 19 x, 19 y and 19 z respectively engagethe straight guide grooves 14 x, 14 y and 14 z, but do not contact theguide member 13. Moreover, in FIG. 9D, the rolling balls 19 x, 19 y and19 z contact the guide member 13, but do not contact the moving member14. As illustrated in FIG. 9D, the rolling ball 19 z overlaps with thestraight guide groove 14 z by an interval “b” in the z-axis directionwhen contacting the guide member 13, thus being prevented from fallingfrom the straight guide groove 14 z. In addition, the rolling balls 19 xand 19 y each overlap with the straight guide grooves 14 x and 14 y byan interval “b” in the z-axis direction, thus being prevented fromfalling the straight guide groove 14 x and 14 y.

As mentioned above, providing the plurality of the restriction parts 14v and the stoppers 14 w, which respectively engage the plane parts 13 vand 13 w, can prevent the rolling balls 19 x, 19 y and 19 z fromfalling. In particular, the restriction parts 14 v and the stoppers 14 wmay be provided so that the interval “a” is shorter than an interval cfrom a setting surface 14 e of the moving member 14 to a position whereeach rolling member engage the corresponding straight guide groove. Inthis example, the restricting parts 14 v and the stoppers 14 w areprovided so that the each rolling ball overlaps with the moving member14 by the interval “b” when the guide member 13 moves in the y-axisdirection, that is, so that part of each rolling ball is positionedinside each straight guide groove. In this example, the motor unit 1000Aaccording to this example includes the three rolling balls 19 x, 19 yand 19 z, but the present invention is not limited to this. For example,the three or more rolling balls may be provided, and the guide part ofthe guide member 13 and the straight guide groove of the moving member14 may be formed according to the rolling balls. However, when the threeor more rolling balls are provided, some rolling balls fail to engagethe guide part and the straight guide groove due to production error ofthe rolling balls and the straight guide grooves, and thus the movingmember 14 hardly moves highly accurately. Accordingly, to move themoving member 14 highly accurately, the number of the rolling balls ispreferably three.

Moreover, in this example, as illustrated in FIG. 8B, the spring hookparts of the moving member 14 are disposed in a projection plane in they-axis direction of the guide member 13. Specifically, the spring hookparts are disposed to sandwich the straight guide grooves 14 x, 14 y and14 z, the guide wall 13 x-y, and the guide plane part 13 z. Such anarrangement can utilize a space (space on a rear side of a surfaceprovided with the guide wall 13 x-y and the guide plane part 13 z) on apositive side of the y-axis of the guide member 13 effectively. Theconical hole part 14 a engaging the reference ball 17, the hook part 14b engaging the integrated spring 15, and an interlocking part 14 ddescribed later are also disposed in the projection plane in the y-axisdirection of the guide member 13. In particular, each member is disposedto sandwich the straight guide grooves 14 x, 14 y and 14 z, the guidewall 13 x-y, and the guide plane part 13 z. Utilizing the space on thepositive side of the y-axis of the guide member 13 can miniaturize themotor unit 1000A.

In this example, with the above configuration, it is impossible toassemble the guide member 13, the moving member 14 and the rolling balls19 x, 19 y and 19 z in the y-axis direction. Thus, in this example, whenthe rolling balls 19 x, 19 y and 19 z on the straight guide grooves 14x, 14 y and 14 z of the moving member 14 are inserted in the guidemember 13 by sliding in a direction of an arrow S, a state of FIG. 10Aor 10B becomes a built-in state illustrated in FIG. 8A.

FIG. 11A is a perspective view of a lens driving unit in a state wherethe motor unit 1000A is attached. FIG. 11B is a perspective view of thelens driving unit in a state where the motor unit 1000A is not attached.FIG. 11C is a diagram illustrating a coupling part of the motor unit1000A and a lens unit 300. FIG. 11D is a sectional view of the couplingpart. The lens unit 300 is supported to be movable along the opticalaxis (x-axis) by a configuration of a bar and a sleeve. Guide bars 301and 302 are formed to be parallel to the x-axis, being supported by anunillustrated member. An interlocking member 303 is integrated with thelens unit 300 in the optical axis direction through an interlockingbiasing spring 304, and rotating force in a direction of an arrow R isapplied to the coupling member 303.

As illustrated in FIG. 11D, on the interlocking part 14 d provided onthe moving member 14, a groove shape having an opening angle of 60degrees is formed. By the rotating force in the direction of the arrow Rillustrated in FIG. 11B, a spherical interlocking part 303 a provided onthe interlocking member 303 engages the groove shape formed on theinterlocking part 14 d, and driving force of the motor unit 1000A istransmitted to the lens unit 300 through the interlocking member 303.The rotating force in the direction of the arrow R of the interlockingmember 303 is also received by the guide member 13 through the rollingballs 19 x, 19 y and 19 z. Additionally, positional error in the y-axisdirection between the motor unit 1000A and the lens unit 300 is absorbedby the rotation of the interlocking member 303 in the direction of thearrow R, and positional error in the z-axis direction between them isabsorbed by moving the engagement position of the groove shape formed onthe interlocking part 14 d and the spherical interlocking part 303 a inthe z-axis direction. Thus, even when error in production exits, themotor unit 1000A enables the lens unit 300 to smoothly and certainlymove along the optical axis.

SECOND EXAMPLE

Referring to FIGS. 12A, 12B, 13, and 14A to 14C, a description will begiven of a configuration of a vibration-wave motor unit (an ultrasonicmotor unit, hereinafter, referred to as “motor unit”) 1000B according tothis example. FIGS. 12A and 12B are perspective views of the motor1000B. FIG. 12A is a perspective view as seen form a top side, and FIG.12B is a perspective view as seen from a bottom side. FIG. 13 is anexploded perspective view of the motor unit 1000B. FIGS. 14A to 14C area plan view and sectional views of the motor unit 1000B. FIG. 14A is aplan view, and FIGS. 14B and 14C are sectional views taken along an x-xline and a z-z line of FIG. 14A, respectively.

The vibrator 2 included in the motor unit 1000B according to thisexample is identical with the vibrator 2 of the first example. A basemember 105 is fixed to a fixing member (not illustrated) by the screws,and fixes a friction member 107 using the screws. The friction member107 comes into frictional contact with the driving protrusions 2 a and 2b by pressing force of tension coil springs 110. As well as the firstexample, a flexible substrate 106 is mechanically and electricallyconnected to the piezoelectric element 4 of the vibrator 2 by ananisotropic conductive paste, and applies the two-phase high frequencyvoltages to the piezoelectric element 4. A vibrator holding frame 108 isintegrated with the vibrator 2 by fixing the fixed arm parts 2 c and 2 dwith the adhesive. A pressing intermediary member 109 includes a felt109 a that contacts the vibrator 2, and a high rigid plate 109 b, suchas the metal, that receives the pressing force of the tension coilsprings 110. The felt 109 a transmits the pressing force of the tensioncoil springs 110 to the vibrator 2 without preventing the vibrationsenergized in the vibrator 2. The four tension coil springs (biasingmembers) 110 are disposed around the vibrator 2, and, as describedabove, generate the pressing force as pressers in this example. Apressing plate (first pressing member) 111 is biased by the tension coilsprings 110. The pressing plate 111 also includes two sphericalprotrusions (pressing parts) 111 a that abuts against the pressingintermediately member 109 and that are equally positioned in the y-axisdirection. The two spherical protrusions 111 a are provided to besymmetric with respect to the left/right symmetric plane D in thefront/rear symmetric plane C of the vibrator 2. A moving member outerframe 112 is integrated with a moving member (second pressing member)114 by the screws. A guide member 113 is fixed to the base member 105 bythe screws through a fixed sheet metal 116 to be parallel to a contactsurface of the friction member 107 with the driving protrusions 2 a and2 b. The moving member 114 is biased by the tension coil springs 110.Rolling balls (rolling members) 119 x, 119 y and 119 z each aresandwiched between the guide member 113 and the moving member 114, andreceives the pressing force of the tension coil springs 110. In thisexample, a moving part, which includes the vibrator 2, the vibratorholding frame 108, the pressing intermediary member 109, the tensioncoil springs 110, the pressing plate 111, the moving member outer frame112, and the moving member 114, relatively moves along the x-axis withrespect to the friction member 107.

Next, referring to FIGS. 15A to 15C, a description will be given of adegree of freedom in motion of the vibrator 2 according to this example.FIGS. 15A to 15C are explanatory diagrams of the degree of freedom inmotion of the vibrator 2. In FIGS. 15A to 15C, components of the motorunit 1000B unnecessary for the explanation are omitted. FIG. 15Aillustrates the moving member outer frame 112 and the moving member 114,which are integrated with the vibrator holding frame 108. FIG. 15Billustrates a sectional view of the configuration illustrated in FIG.15A cut on a plane containing a reference bar 117, and a biased bar 118.FIG. 15C illustrates a sectional view of the configuration illustratedin FIG. 15A cut on the left/right symmetric plane D of the vibrator 2.

An integrated spring 115 is a plate spring fixed to a spring attachmentpart 112 b provided on the moving member outer part 112, and biases aplane part 108 b formed on the vibrator holding frame 108 in a directionof an arrow D through the biased bar 118. Moreover, a plane part 108 aformed on the vibrator holding frame 108 receives reaction force in adirection of an arrow E in balance with the biasing force in thedirection of the arrow D through the reference bar 117 sandwichedbetween the plane part 108 a and a plane part 112 a formed on the movingmember outer part 112. Thus, the vibrator 108 and the moving part outerframe 112 are integrated in the x-axis direction by the biasing force ofthe integrated spring 115 through the reference bar 117 and the biasedbar 118. Additionally, sandwiching the reference bar 117 between theplane part 112 a and the plane part 108 a also restricts the rotation ofthe vibrator holding part 108 in the yaw direction. Furthermore, thevibrator holding frame 108 fits within the moving part outer frame 112in the z-axis direction, thus restricting the rotation of the vibratorholding frame 108 in the z-axis direction (z-axis translation direction)and the roll direction.

As described above, the motion of the vibrator holding frame 108, whichis integrated with the vibrator 2 with respect to the moving member 114,has two degrees of freedom in the y-axis direction (y-axis translationdirection) and the pitch direction. In this example, the vibrator 2 hasthe two degrees of freedom in the y-axis direction and the pitchdirection, thus enabling the driving protrusions 2 a and 2 b of thevibrator 2 to certainly abut against the friction member 107. Inaddition, the driving protrusions 2 a and 2 b, and the friction member107 move by the rotation of the reference bar 117 and the biased bar118, and thus can decrease friction of the motion. Furthermore, thebiasing force in the direction of the arrow D and the reaction force inthe direction of the arrow E balance within one plane, thus notgenerating unbalance of unnecessary force to the driving protrusions 2 aand 2 b.

FIG. 16 is an explanatory diagram of a relation between the pressingplate 111 and the moving member 114. The four tension coil springs 110engage each of spring hook parts of the pressing plate 111 and themoving member 114. As a distance in the y-axis direction between thepressing plate 111 and the moving member 114 is determined byunillustrated components of the motor unit 1000B, the four tension coilsprings 110 bias the pressing plate 111 and the moving member 114. Inthis example, the two spherical protrusions 111 a, which are equallypositioned in the y-axis direction, abut against the pressingintermediary member 109, and the pressing plate 111 has the degree offreedom in motion (tilt) in the pitch direction with the two sphericalprotrusions 111 a as a fulcrum. In other words, the pressing part 111can tilt around the axis orthogonal to the left/right symmetric plane Din the front/rear symmetric plane C. The pressing part need not bestrictly tiltable around the above axis, and is regarded to be tiltablearound the above axis even when shifting by a few mm from the aboveaxis. For example, although being different according to performance anda use, shifts may be about ±0.2 mm. Accordingly, the pressing force ofthe four tension coil springs 110 acting on the driving protrusions 2 aand 2 b from the two spherical protrusions 111 a through the pressingintermediary member 109 each are adjusted optimally.

Moreover, as the pressing plate 111 has the degree of freedom in motionin the pitch direction relative to the vibrator holding frame 108including the pressing intermediary member 109, an attitude of thepressing plate 111 with respect to the moving member 114 is adjusted tobe an optimum state regardless of a tilt of the vibrator holding frame108 and a change of the tilt. In addition, although the distance in they-axis direction between the pressing plate 111 and the moving member114 may change, a spring constant of the tension coil springs 110 can besmaller than that of a plate spring, and this is advantageous tostabilization of the pressing force.

Besides, as a protrusion 111 b provided on the pressing plate 111engages a groove part 108 c as illustrated in FIG. 15B formed on thevibrator holding frame 108, the pressing plate 111 and the moving member114 are integrated in the x-axis direction through the vibrator holdingframe 108. Accordingly, the pressing force of the tension coil springs110 becomes stable without changing a positional relation among thetension coil springs 110, the pressing plate 111, and the moving member114 while the motor unit 1000B moves along the x-axis.

FIG. 17 is a perspective view of a straight guide member including theguide member 113, the moving member 114, and the rolling balls 119 x,119 y and 119 z, which are sandwiched between both members. A relationamong the guide member 113, straight guide grooves 114 x, 114 y and 114z formed on the moving member 114, and the rolling balls 119 x, 119 yand 119 z are the same as that in the first example, and thus theexplanation thereof is omitted. On the guide member 113, plane parts 113v and 113 w are formed. The moving member 114, as described above,includes the four spring hook parts that each engage the tension coilsprings 110. As with the first example, a restriction part 114 v, whichis part of each of two of the four hook spring hook parts, is providedto have an interval “a” to the plane part 113 v in the y-axis directionin the state where the guide member 113 and the moving member 114 abutagainst each rolling balls.

On the moving member 114, two stoppers 114 w are also provided to havean interval “a” to the plane part 113 w in the y-axis direction in thestate where the guide member 113 and the moving member 114 abut againsteach rolling ball. The above configuration prevents the rolling balls119 x, 119 y and 119 z from falling. Moreover, in this example, as withthe first example, the hook spring parts of the moving member 114 aredisposed in a projection plane in the y-axis direction of the guidemember 113. Such an arrangement can utilize a space on a positive sideof the y-axis of the guide member 113 effectively, and can miniaturizethe motor unit 1000B.

The motor unit 1000B according to this example is served as part of alens driving unit to drive a lens unit along the optical axis. FIGS. 18Band 18B are explanatory diagrams of a coupling part of the motor unit1000B and the lens unit. As with the first example, by rotational forcein the direction of the arrow R in FIG. 11B, a spherical interlockingpart 112 c provided on the moving part outer frame 112 engages aninterlocking groove 401 a that is formed on an interlocking member 401provided on the lens unit and has an opening angle of 60 degrees.Accordingly, the driving force from the motor unit 1000B is transmittedto the interlocking member 401 through the moving member outer frame112. Moreover, as the same driving force in the direction of the arrow Rillustrated in FIG. 11B in the first example is received by the guidemember 113 through the moving member 114, which is integrated with themoving member outer frame 112, and the rolling balls 119 x, 119 y and119 z, unnecessary force is not transmitted to the vibrator holdingframe 108.

THIRD EXAMPLE

Referring to FIGS. 19A, 19B, 20, and 21A to 21C, a description will begiven of a configuration of a vibration-wave motor unit (an ultrasonicmotor unit, hereinafter, referred to as “motor unit”) 1000C according tothis example. FIGS. 19A and 19B are perspective views of the motor unit1000C. FIG. 19A is a perspective view as seen form a top side, and FIG.19B is a perspective view as seen from a bottom side. FIG. 20 is anexploded perspective view of the motor unit 1000C. FIGS. 21A to 21C area plan view and sectional views of the motor unit 1000C. FIG. 21A is aplan view, and FIGS. 21B and 21C are sectional views taken along an x-xline and a z-z line of FIG. 21A, respectively.

The motor unit 1000C according to this example includes a first vibrator2_1 and a second vibrator 2_2. The first and second vibrators 2_1 and2_2 each are the same as the vibrator 2 in the first and secondexamples. The first and second vibrators 2_1 and 2_2 sandwiches afriction member 207. Driving protrusions 2 a_1 and 2 b_2 of the firstvibrator 2_1 abut against a first abutment surface 207_1 on a firstvibrator 2_1 side of the friction member 207. Driving protrusions 2 a_2and 2 b_2 of the second vibrator 2_2 abut against a second abutmentsurface 207_2 on a second vibrator 2_2 side of the friction member 207.

A base member 205 is fixed to a fixing member (not illustrated) by thescrews. Flexible substrates 206_1 and 206_2 are mechanically andelectrically connected to the first and second vibrators 2_1 and 2_2,respectively, to vibrate the first and second vibrators 2_1 and 2_2. Afirst vibrator holding frame 208_1 is integrated with the first vibrator2_1 by fixing fixed arm parts of the first vibrators 2_1 with theadhesive, and a second vibrator holding frame 208_2 is integrated withthe second vibrator 2_2 by fixing fixed arm parts of the second vibrator2_2 with the adhesive. A pressing intermediary member 209 includes afelt 209 a that contacts the first vibrator 2_1, and a high rigid plate209 b, such as the metal, that receives pressing force of tension coilsprings 210. The felt 209 a transmits the pressing force of the tensioncoil springs 210 to the first vibrator 2_1 without preventing thevibrations energized in the first vibrator 2_1. The two tension coilsprings (biasing members) 210 are disposed around the first and secondvibrators 2_1 and 2_2, and, as described above, generate the pressingforce as pressers in this example. A first pressing plate (firstpressing member) 211 is biased by the tension coil springs 210. Thefirst pressing plate 211 also includes a spherical protrusion (pressingpart) 211 a that abuts against the pressing intermediately member 209 onan intersection line of a front/rear symmetric plane C and a left/rightsymmetric plane D of the first vibrator 2_1.

A first coupling sheet metal 212_1 and a second coupling sheet metal212_2 are respectively fixed to the first and second vibrator holdingframes 208_1 and 208_2 by the screws. A second pressing plate (secondpressing member) 213 is biased by the tension coil springs 210. A felt214 transmits the pressing force of the tension coil springs 210 to thesecond vibrator 2_2 without preventing the vibrations energized in thesecond vibrator 2_2. An integrated spring 215 is a tension coil springthat are hooked between a hook part 212 b_1 provided on the firstcoupling sheet metal 212_1 and a hook part 212 b_2 provided on thesecond coupling sheet metal 212_2. The integrated spring 215 biases thefirst and second vibrator holding frames 208_1 and 208_2 through thefirst and second coupling sheet metals 212_1 and 212_2. The first andsecond vibrator holding frames 208_1 and 208_2, which are biased by theintegrated spring 215, are integrated with the base member 205 in thex-axis direction.

In this example, a moving part, which includes each vibrator, eachvibrator holding frame, the pressing intermediary member 209, thetension coil springs 210, each pressing plate, each coupling sheetmetal, and the felt 214, relatively moves along the x-axis with respectto the friction member 207. The first vibrator 2_1, the first vibratorholding frame 208_1, and the first coupling sheet metal 212_1 areidentical with the second vibrator 2_2, the second vibrator holdingframe 208_2, and the second coupling sheet metal 212_2, respectively.

Next, a description will be given of a degree of freedom in motion ofthe first and second vibrators 2_1 and 2_2 according to this example.FIGS. 22A and 22B are explanatory diagrams of the second vibrator 2_2.In FIGS. 22A and 22B, components of the motor unit 1000C unnecessary forthe explanation are omitted.

FIG. 22A illustrates the second vibrator holding member 208_2 and thebase member 205 that are integrated by the integrated spring 215 throughthe second coupling sheet metal 212_2. A reference ball 217_2 issandwiched between a conical hole part 212 a_2 formed on the secondcoupling sheet metal 212_2 and a conical hole part 205 a_2 formed on thebase member 205. A ball 218_2 is sandwiched between a plane part 208 a_2of the second vibrator holding frame 208_2 and a conical hole part 205b_2 formed on the base member 205. Sandwiching the ball 218_2 betweenthe plane part 208 b_2 and the conical hole part 205 c_2 restricts therotation of the second vibrator holding frame 208_2 around the referenceball 217_2 with respect to the base member 205.

FIG. 22B illustrates a sectional view of the motor unit 1000C cut on aplane containing a setting center of the integrated spring 215, thereference ball 217_2, and the ball 218_2. Arrows A to C each representforce acting on the second vibrator holding frame 208_2. The forcerepresented by the arrow A is force for biasing the second vibratorholding frame 208_2 by the integrated spring 215 to rotate the secondvibrator holding frame 208_2 in the rotational direction (yaw direction)around the y-axis centering the reference ball 217_2. The forcerepresented by the arrow B is a force for acting on the second vibratorholding frame 208_2 by the ball 218_2. As described above, sandwichingthe ball 218_2 between the plane part 208 b_2 and the conical hole part205 c_2 restricts the rotation of the second vibrator holding frame208_2 around the reference ball 217_2 with respect to the base member205. Thus, the rotation of the second vibrator holding frame 208_2 inthe yaw direction is restricted. Then, moments of the forces A and Baround the reference ball 217_2 balances.

The force C is force for acting on the second vibrator holding frame208_2 through the second coupling sheet metal 212_2, balancing withresultant force of the forces A and B as illustrated in FIG. 22C. Thus,the degree of freedom in motion in the x-axis direction (x-axistranslation direction) and the z-axis direction (z-axis translationdirection) of the second vibrator holding frame 208_2 is restricted.Moreover, as the reference ball 217_2 is sandwiched between the conicalhole part 212 a_2 and the conical hole part 205 a_2, the degree offreedom in motion in the y-axis direction (y-axis translation direction)of the second vibrator holding frame 208_2 is also restricted.

As described above, in this example, the motion of the second vibratorholding frame 208_2, which is integrated with the second vibrator 2_2,with respect to the base member 205 has two degrees of freedom in arotational direction (roll direction) around the x-axis and a rotationaldirection (pitch direction) around the z-axis. In this example, as thesecond vibrator 2_2 has the two degrees of freedom in motion in the rolldirection and in the pitch direction, the driving protrusions 2 a_2 and2 b_2 of the second vibrator 2_2 can abut against the second abutmentsurface 207_2 of the friction member 207 certainly. Additionally, theforces A to C, which restrict the degree of freedom in motion of thesecond vibrator 2_2, balance within one plane, thus not generatingunbalance of unnecessary force to the driving protrusions 2 a_2 and 2b_2. The rotation of the second vibrator holding frame 208_2 around thereference ball 217_2 with respect to the base member 205 is identicalwith the rotation of the vibrator holding frame 8 in the roll directionand the pitch direction around the reference ball 17 illustrated inFIGS. 6D and 6E of the first example.

Though not being illustrated in FIGS. 22A and 22B, the first vibrator2_1, the first vibrator holding frame 208_1, and the first couplingsheet metal 212_1 are arranged at a position where the second vibrator2_2, the second vibrator holding frame 208_2, and the second couplingsheet metal 212_2 are rotated by 180 degrees around the z-axis. Thereference ball 217_1 is sandwiched between a conical hole part formed onthe first coupling sheet metal 212_1 and a conical hole part 205 a_1formed on the base member 205. The ball 218_1 is also sandwiched betweena plane part 208 a_1 of the first vibrator holding frame 208_1 and aconical hole part 205 b_1 formed on the base member 205. Further, thereference balls 217_1 and 217_2 are disposed on the same sectional viewillustrated in FIG. 22B. Thus, in this example, the degree of freedom ofthe first vibrator holding frame 208_1, which is integrated with thefirst vibrator 2_1, with respect to the base member 205 has two degreeof freedom in the roll direction and the pitch direction. In thisexample, as the first vibrator 2_1 has the degree of freedom in motionin the roll direction and in the pitch direction, the drivingprotrusions 2 a_1 and 2 b_1 of the first vibrator 2_1 can abut againstthe first abutment surface 207_1 of the friction member 207 certainly.

In this example, driving the first and second vibrators 2_1 and 2_2,which sandwich the friction member 207, at the same time can generatelarger thrust force compared with case of driving one vibrator.Increasing the biasing force of the integrated spring 215 according tothe generated thrust force is necessary, but using the tension coilspring as the integrated spring 215 can save a space and can make thedegree of freedom for setting the biasing force larger compared with theplate spring. As each pressing force of the tension coil springs 210, bywhich each vibrator abuts against the friction member 207, also balancesacross the friction member 207, the straight guide part explained in thefirst and second examples to smoothly guide the motion while receivingthe pressing force is unnecessary in this example.

FIG. 23 is an explanatory diagram of a relation between the first andsecond pressing plates 211 and 213. The two tension coil springs 210engage each hook part of the first and second pressing plates 211 and213. As a distance in the y-axis direction between the first and secondpressing plates 211 and 213 is determined by unillustrated components ofthe motor unit 1000C, the two tension coil springs 210 bias the firstand second pressing plates 211 and 213. The two tension coil springs 210each are disposed at the position diagonal to each other with respect tothe spherical protrusion 211 a and have the same specification. However,biasing force of each tension coil spring at a predetermined length isnot necessarily the same due to production tolerance, and error in aposition of each spring hook part of the first and second pressingplates 211 and 213 is also caused due to production precision in asingle part and production error of intervening parts. In this example,the first pressing plate 211 is abutted against the pressingintermediary member 209 by the spherical protrusion 211 a, and has thedegree of freedom in motion (tilt) in the roll direction and the pitchdirection with the spherical protrusion 211 a as a fulcrum. In otherwords, the first pressing part 211 can tilt around the axis orthogonalto the front/rear symmetric plane C in the left/right symmetric plane Dand around the axis orthogonal to the left/right symmetric plane D inthe front/rear symmetric plane C. The first pressing part need not bestrictly tiltable around each axis, and is regarded to be tiltablearound each axis even when shifting by a few mm from each axis. Forexample, although being different according to performance and a use,shifts may be about ±0.2 mm. Accordingly, the pressing force of the twotension coil springs 210 acting on the driving protrusions 2 a_1 and 2b_1 from the spherical protrusion 211 a through the pressingintermediary member 209 each are adjusted optimally with respect to theproduction tolerance. As the second vibrator 2_2 also receives thereaction force from the second pressing plate 213, the optimallyadjusted processing force is applied to the driving protrusions 2 a_2and 2 b_2.

Moreover, the first pressing plate 211 relatively has the degree offreedom in motion in the roll direction and the pitch direction withrespect to the first and second vibrator holding frames 208_1 and 208_2.Thus, regardless of a tilt of the first and second vibrator holdingframes 208_1 and 208_2 and a change of the tilt, an attitude of thefirst pressing plate 211 is adjusted to be an optimum state and thepressing force of each of the two tension coil springs 210 becomesstable without variations.

A protrusion 211 b provided on the first pressing plate 211 engages agroove 208 c_1 formed on the first vibrator holding frame 208_1illustrated in FIG. 19A. A protrusion 213 b provided on the secondprocessing plate 213 also engages a groove 208 c_2 formed on the secondvibrator holding frame 208_2 illustrated in FIG. 19B. Thus, the firstand second pressing plates 211 and 213 are integrated in the x-axisdirection through the first and second vibrator holding frames 208_1 and208_2. Accordingly, a positional relation among the tension coil springs210, the first pressing plate 211 and the second pressing plate 213 isnot changed while the moving part moves along the x-axis, and thepressing force of the tension coil springs 210 becomes stable.

FIGS. 24A and 24B are perspective views of a lens driving unit. FIG. 24Aillustrates the lens driving unit to which the motor unit 1000C isattached. FIG. 24B illustrates the lens driving unit to which the motorunit 1000C is not attached. A lens unit 500 is supported to be movablealong the optical axis (x-axis) by a configuration of a bar and asleeve. Guide bars 501 and 502 are formed to be parallel to the x-axis,being supported by an unillustrated member. The friction member 207provided on the motor unit 1000C is integrated with the lens unit 500 bythe screws and with the adhesive, allowing thrust force to move in theoptical axis direction to act the lens unit 500.

The number of the tension coil springs 110 is four in the first andsecond examples, and is two in the third example, but may be othernumbers. Moreover, in the third example, an engagement relation betweenthe first and second pressing plates 211 and 213 may be switched in aheight direction, and a compression coil spring may be used as thepressers instead of the tension coil spring.

Furthermore, an expression “each member exists in a plane” in eachexample may be interpreted that at least part of the member intersectsthe surface.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2016-091507, filed on Apr. 28, 2016, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A motor comprising: a first vibrator; a contactmember in contact with the first vibrator; a plurality of biasing partsgenerating a biasing force; and a pressing member pressing the firstvibrator onto the contact member by the biasing force, wherein the firstvibrator and the contact member are arranged to perform relativemovement with respect to each other by vibrations that occur in thefirst vibrator, wherein the first vibrator is arranged to be tiltablearound a first axis along a first direction orthogonal to both of amoving direction of the relative movement and a biasing direction of theplurality of biasing parts, and wherein the pressing member is arrangedto be tiltable around a second axis along the first direction withrespect to the first vibrator.
 2. The motor according to claim 1,wherein the pressing member includes a pressing part for pressing thefirst vibrator by the biasing force.
 3. The motor according to claim 1,wherein the pressing member is configured to move with the firstvibrator.
 4. The motor according to claim 2, wherein the pressing partis disposed in a first plane that is parallel to both of the firstdirection and the biasing direction and that symmetrically divides afacing area of the first vibrator facing the contact member.
 5. Themotor according to claim 4, wherein the second axis is orthogonal to asecond plane, which is parallel to both of the moving direction and thebiasing direction and symmetrically divides the facing area, and thesecond axis is positioned in the first plane.
 6. The motor according toclaim 5, wherein the pressing part is disposed in the second plane, andwherein the second axis is orthogonal to the first plane and ispositioned in the second plane.
 7. The motor according to claim 1,further comprising a second vibrator in contact with the contact memberon a surface of the contact member opposite to a surface of the contactmember where the first vibrator is in contact with the contact member,wherein the pressing member presses the second vibrator onto the contactmember by the biasing force of the plurality of biasing parts.
 8. Themotor according to claim 1, wherein each of the plurality of biasingparts includes a coil spring.
 9. The motor according to claim 1, whereineach of the plurality of biasing parts includes a tension coil spring.10. The motor according to claim 1, wherein the first vibrator includesprotrusions that abut on the contact member.
 11. The motor according toclaim 1, wherein the first vibrator includes a vibration plate incontact with the contact member, and a piezoelectric element configuredto excite vibration in the vibration plate.
 12. An apparatus comprising:a motor; and a member moved by a force generated by the motor, whereinthe motor includes: a first vibrator; a contact member in contact withthe first vibrator; a plurality of biasing parts generating a biasingforce; and a first pressing member pressing the first vibrator onto thecontact member by the biasing force; and wherein the first vibrator andthe contact member are arranged to perform relative movement withrespect to each other by vibrations that occur in the first vibrator,wherein the first vibrator is arranged to be tiltable around a firstaxis along a first direction orthogonal to both of a moving direction ofthe relative movement and a biasing direction of the plurality ofbiasing parts, and wherein the pressing member is arranged to betiltable around a second axis along the first direction with respect tothe first vibrator.
 13. The apparatus according to claim 12, wherein theapparatus includes an optical apparatus including a lens as the membermoved by the force generated by the motor.
 14. The motor according toclaim 1, wherein the plurality of biasing parts are disposed around thefirst vibrator.
 15. The apparatus according to claim 12, wherein theplurality of biasing parts are disposed around the first vibrator. 16.The motor according to claim 2, wherein the pressing member includes twoof the pressing part, the two of the pressing part being arranged alongthe first direction.
 17. The apparatus according to claim 12, whereinthe pressing member includes two of a pressing part for pressing thefirst vibrator by the biasing force, the two of the pressing part beingarranged along the first direction.